How to create a custom API endpoint to call a custom function in Acumatica?

Hi everyone,

I’m trying to create a custom API endpoint in Acumatica that simply calls a custom function inside my code (for example, to run some business logic or integration helper).

Basically, I have a function inside a helper class (for example: AuthorizeExistingPayment()), and I’d like to expose it through the Acumatica REST API so I can call it externally — something like:

POST /entity/CustomAPI/1.0/MyFunction/Run

However, I’m not sure what’s the correct approach in Acumatica to make this work.
 

However, I’m not sure what’s the correct approach in Acumatica to make this work.
I’ve seen some examples using:

• A custom BLC (Business Logic Controller) class that defines a PXAction,

• Or a custom screen with a PXFilter and PXAction,

• Then linking that to a Web Service Endpoint.
   

  

  

  

  

  

   

But I’m still confused about which method is recommended for simple custom APIs that only need to:

• Receive some JSON parameters,

• Execute my internal function,

• And return a custom response (without saving anything to the database).

Can anyone please explain the recommended way to create a REST-exposed custom function in Acumatica?
Specifically:

1. Should I create a new screen, or a pure BLC (graph without UI)?

2. How do I register it correctly in Web Service Endpoints?

3. Is there an example of a minimal “Custom Function API” pattern (with Request/Response DACs)?

Thank you in advance for any examples or best practices